A former Staten Island assistant principal turned a 12-year-old female student into his office masseuse, and then pleaded with her to lie about it to investigators, a new report charged.

Lawrence Siegel, 56, who retired as assistant principal of IS 72 in New Springville over the summer, was initially cleared of wrong-doing after a call to 311 accused of him of soliciting shoulder rubs from female students in his office.

But a second investigation by the Office of the Special Commissioner of Investigation, Richard Condon, found that Siegel had subverted the first inquiry by pleading with one girl to “keep quiet” about their interactions.

“If you do this for me, I will take care of you for life,” Siegel told the girl, according to a recording her mother made of the phone conversation that was quoted in the report.

The girl, who Condon’s office declined to name, admitted that had she had initially lied to investigators.